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HardenersHardener

LNB77

LNB77 hardener for polyurethane coatings

Milesi polyurethane (isocyanate) hardener, component B for 2K PU coatings. The dealer calls it a 'hardener for PU primers and matt lacquers'. It is the standard hardener for the LGA21/LGA210/LGA22 clear PU lacquers, the LGA531–536 thixotropic series, the LBA521/LBA528 PU sealers, LBR102 white, LBR90 black and LBR21811 MDF isolating primer, plus the KGA1 and KKR1 tinting converters. Low solids (23–25 %), so it goes in at a high dose — 40–50 % of the base. Probably aromatic-type (the mix TDSs make no yellowing-resistance claim for it, unlike LNB20/LNB190): for whites and pale finishes Milesi offers LNB20/LNB190. Compared with LNB42 it gives a more elastic film and slightly lower gloss.

  • second component of LGA21 (40 gloss), LGA210 (30 gloss), LGA22 (20 gloss) clear PU lacquers
  • second component of the LGA531–LGA536 thixotropic PU lacquers (65–3 gloss), incl. electrostatic
  • second component of the LBA521 and LBA528 clear PU sealers
  • second component of the LBR102 white, LBR90 black (for PU foam) and LBR21811 MDF isolating PU primers
  • second component of the KGA1 clear and KKR1 white tinting converters

Ask about LNB77

Answers are based on the LNB77 data and the products it mixes with.

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Mixing matrix

  • KGA1base
    % by weight: 50 %official% by volume: 50 %official

    clear 20-gloss PU converter for tinting; thinner LZC1026/LZC8643 20–30 %

  • KKR1base
    % by weight: 50 %official% by volume: 67 %official

    white 20-gloss PU converter; thinner LZC8643 10–30 %

  • LBA521base
    % by weight: 50 %official% by volume: 50 %official

    clear thixotropic PU sealer; thinner LZC1026/LZC1051 10–30 %

  • LBA528base
    % by weight: 50 %official% by volume: 50 %official

    clear thixotropic high-solids PU sealer; thinner LZC1026/LZC1051/LTC40 10–30 %

  • LBR102base
    % by weight: 50 %official% by volume: 65 %official

    white thixotropic PU primer (LNB613 alternative at 40 wt% / 55 vol%); thinner LZC1026/LZC1051/LZC8643 10–30 %

  • LBR21811base
    % by weight: 40 %official% by volume: 45 %official

    PU isolating primer for MDF; thinner LZC1026/LZC1051/LZC8643 10–40 %

  • LBR90base
    % by weight: 40 %official% by volume: 50 %official

    black PU primer for PU foam — LNB77 is the only listed hardener; thinner LZC1026/LZC1051 10–30 %

  • LGA21base
    % by weight: 50 %official% by volume: 50 %official

    PU lacquer 40 gloss; thinner LZC1051 10–30 %

  • LGA210base
    % by weight: 50 %official% by volume: 50 %official

    PU lacquer 30 gloss — LNB77 is the only listed hardener; thinner LZC1051 20–30 %

  • LGA22base
    % by weight: 50 %official% by volume: 50 %official

    PU lacquer 20 gloss — LNB77 is the only listed hardener; thinner LZC1026/LZC1051 10–30 %

  • LGA531base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 65 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA532base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 45 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA533base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 30 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA534base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 20 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA535base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 10 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA536base
    % by weight: 50 %official% by volume: 50 %official

    thixotropic PU lacquer 3 gloss (LGA53x series, electrostatic-capable); thinner S50/S70/S80 10–30 %

  • LGA84base
    % by weight: 50 %dealer

    Clear PU sealer-topcoat LGA84 (20 gloss) / LGA83 (35 gloss). Technocolor lists LNB21/LNB42 for LGA84; a Ukrainian dealer (paraphrasing the Milesi TDS) gives 50 % LNB77 or LNB42. Use LNB77 when you need a more elastic film; gloss drops a few units. Thinner LZC1026 20–30 %, pot life 2–3 h.

    Source is a Ukrainian dealer; t-color.ru lists LNB21/LNB42 for LGA84, not LNB77.

  • LGA20base
    % by weight: 50 %datasheet% by volume: 51.1 %datasheet

    PU lacquer 53 gloss from the same LGA2x series: Milesi TDS gives LNB77 at 50 %, pot life 3–4 h.

    Technocolor's LGA20 page lists no hardener or thinner at all — data is only from the Milesi TDS (LNB77 or LNB7, 50 %).

  • LZC1026 / LZC1051 / LZC8643 / LTC40 / S50 / S70 / S80Thinner
    % by weight: 10–40 %official% by volume: 10–50 %official

    LZC1026/LZC1051/LZC8643 for the LBA/LBR primers, LGA2x lacquers and KGA1/KKR1 converters (usually 10–30 %, LBR21811 up to 40 %); S50/S70/S80 for the LGA53x series (10–30 %).

    Never thin the hardener on its own — thinner goes into the mixed A+B.

Percentages are per 100 parts of component A.

Characteristics

Solids
25 ± 1 %dealer
Density
0.963 ± 0.030 kg/ldatasheet
Pot life · By base
2 h, 3 h, 3 h, 3–4 h, 3 h, 2–3 h
Drying · Conditions
18–22 °C, 65–70 % RH
Gloss · Items
On LGA84, LNB77 gives a few gloss units less than the standard catalysis., On the LGA2x series, LNB14/LNB500 give about 10 gloss units less than LNB77 (LGA21: 40 gloss with LNB77).
Elasticity
On LGA84 it improves film elasticity (the alternative, LNB42, builds more film).dealer
Lightfastness
Probably aromatic type — may yellow; for whites/pale finishes use LNB20 or LNB190.recommended

Application

HVLP

Nozzle · Clear lacquers LGA2x/LGA53x
1.3–1.5
Nozzle · Clear sealers LBA521/LBA528 (converters)
1.5–1.8
Nozzle · Pigmented primers LBR102/LBR90/LBR21811
1.8–2
Pressure · air · Inlet pressure, min
2
Pressure · air · Inlet pressure, max
2.2
Pressure · air · at the cap, max
0.7
Why ru
LNB77 (сухой остаток 23–25 %, очень низкая вязкость) лишь снижает вязкость базы. Прозрачные лаки LGA с сухим остатком ~44–46 % и 50 % LNB77 хорошо распыляются соплом 1,3–1,5 мм; прозрачным тиксотропным изолирующим грунтам LBA и конвертерам KGA1/KKR1 (≈47–66 % сухого остатка: KGA1 47 %, LBA528 50 %, KKR1 66 %) нужно 1,5–1,8 мм; белым/чёрным грунтам LBR с сухим остатком 66–72 % (LBR90 66,5 %, LBR102 71,6 %) — 1,8–2,0 мм (та же логика, что в заметке владельца о недостаточном сопле 1,5 мм для PPS50277). Давления — по практике владельца для HVLP (на входе 2,0–2,2 бар при нажатом курке, ≤ 0,7 бар на воздушной головке).

The hardener is not sprayed on its own — nozzle and pressure follow the mixed base. Airmix/airless for the thixotropic LBA52x/LBR102/LGA53x: 0.009–0.013" tip (0.23–0.33 mm), 60–100 bar fluid, 1–2 bar atomising air. The LGA53x series is also made for electrostatic spraying (80–100 g/m²).

Process and compatibility

Goes with
KGA1, KKR1, LBA521, LBA528, LBR102, LBR21811, LBR90, LGA21, LGA210, LGA22, LGA531, LGA532, LGA533, LGA534, LGA535, LGA536, LGA20, LGA84
Temperature and humidity · Application temperature
15–30datasheet
Temperature and humidity · Min drying temp (°C)
15datasheet
Temperature and humidity · Drying RH %
50–70datasheet
Temperature and humidity · Optimal
18–22 °C, 65–70 % RH, wood moisture 8–14 %datasheet
Mixing
Weigh it, don't eyeball it — the dose is fixed: 50 % for most bases, 40 % for LBR90 and LBR21811. Stir the base, add LNB77, stir the mix, then thin. Stir the mix well again before use (TDS).datasheet
Don'ts
  • don't cut the dose to stretch pot life — an under-cured film stays soft
  • don't leave the can open — isocyanate reacts with air moisture and goes cloudy/gels
  • decant only into suitable containers — polyethylene or stainless steel (TDS)
  • don't apply below 15 °C or above 30 °C

Storage

Shelf life
12 months from productiondatasheet
Storage temperature
0–35 °Cdatasheet
Packaging
0.5 l,2.5 l,5 l,12.5 l,25 ldealer

Safety: Contains isocyanates and organic solvents: flammable, harmful if inhaled, can cause sensitisation. Use a ventilated spray booth, an A2 carbon respirator or air-fed mask, nitrile gloves and goggles; spark-proof equipment, no smoking (TDS). Don't seal leftover mixed material airtight.

Mixed into

KGA1 / KKR1 / LBA521 / LBA528 / LBR102 / LBR21811 / LBR90 / LGA20 / LGA21 / LGA210 / LGA22 / LGA2AA43 / LGA2AA44 / LGA2AA45 / LGA2AA46 / LGA531 / LGA532 / LGA533 / LGA534 / LGA535 / LGA536 / LGA84 / LKR6AB14

Sources

Value tags: “official”, “dealer”, “catalog”, “schedule” are Technocolor data; “workshop” is from our own datasheets; “recommended” is our engineering estimate (hover to see the reasoning).

Not covered by the sources
  • no official t-color.ru page
  • no LNB77 SDS (hazard statements, flash point)
  • isocyanate type (aromatic vs aliphatic) not stated by any source — inferred
  • viscosity of LNB77 not published
  • no Technocolor finishing schedule uses LNB77
  • LNB5 (co-hardener for LBA521/LGA53x) has no data anywhere
  • only the Italian edition of the Milesi TDS was found (EN/RU links 404)
  • LNB7 (Milesi TDS alternative to LNB77 for LGA2x) is not listed by Technocolor